How to spot a liar.

When recruiting potential prospective members for The ShieldWall Network, it’s important that we be able to tell when someone is misrepresenting themselves. Here are a few pointers on how to spot a liar.

by Derek Paulson

Just about everyone you know tells lies. Detecting liars is often the work of the FBI, and they frequently look to facial expressions, body language, and verbal indicators as signals, or “tells,” that someone is lying.

There are many facial expressions and associated reactions that could indicate someone is lying to you. Some are caused by nervousness, some by chemical reactions, and others by physical reactions.

It’s best to observe someone for a while as you make small talk or ask innocuous questions, to see what his usual reactions are.

To start, it’s important to understand how the person in question normally acts.

It’s best to observe someone for a while as you make small talk or ask innocuous questions, to see what his usual reactions are, including tics he may have. Then if he exhibits several lying indicators when you ask more pointed or suggestive questions, and these are not ones he previously performed, you can be confident that he’s likely lying.

Eyes darting back and forth is a physiological reaction to the subject feeling uncomfortable or trapped by your questions that he doesn’t want to answer. It’s a throwback to when people had to seek an escape route when they feared they were in a dangerous situation, such as facing a human or animal adversary.

Rapid blinking is also a tell. A person will ordinarily blink about five or six times a minute, or once every 10 or 12 seconds.

When stressed — for instance, when someone knows he’s lying — he may blink five or six times in rapid succession.
Exceptions to the usual blink rate mostly revolve around production of dopamine in the body. For example, a person with Parkinson’s disease will have a noticeably slower blink rate than what is usual, while a person with schizophrenia will blink more rapidly than normal.

The eyes have it. When a person closes his eyes for a second or two, this may indicate he’s lied to you, since this is a type of defense mechanism. Normally, a person will blink at a speed of 100 to 400 milliseconds, or 0.10 to 0.40 of a second.

Looking up to the right is suspect. When you ask a normal, right-handed person about something he’s supposed to have seen, if he looks upward and to his left, he’s truly accessing his memory of the incident. If he looks upward and to his right, he’s accessing his imagination, and he’s inventing an answer. Left-handed people will usually have just the opposite reactions, and some people will stare straight ahead when trying to recall a visual memory.

Note that different sensations follow the same pattern. If you ask about what a person heard, his eyes will shift toward his left ear to recollect the sound he heard, but if his eyes shift toward his right, he’s about to lie.

The subject’s eyes will shift downward and to his left if he’s going to tell you his memory of a smell or touch or sensation, such as a cold draft or a terrible odor. But his eyes will shift down and to his right if he’s going to lie.

Check also for head shaking. Often when people tell the truth they will nod their heads simultaneously in agreement with what they’re saying. But if they shake their heads in disagreement with what they’ve said, their bodies are betraying their lie.